A founder and first chairman of the 1970 Baltimore City Fair, he was recalled as a promoter of city neighborhoods, sports teams and businesses. His best-known stunt was dressing the mayor in an old-style swimming suit and posing him in a pool with a rubber duck alongside a comely mermaid outside the National Aquarium in 1981.

"Chris was larger than life," said Sandra S. Hillman, a former Schaefer aide who co-conceived the City Fair. "He was a great showman and promoter, a brilliant writer and someone who loved the city. He had a great eye and a greater sense of humor. He was also a caring individual, and if he were your friend, he remained your friend."

Born in New York City and raised in Haddonfield and Moorestown, N.J., he was a graduate of LaSalle College High School in Philadelphia and earned a degree in English at Georgetown University.

In 1967, he joined the staff of the old News American as a reporter and became assistant Sunday editor. In a 1977 article in The Baltimore Sun, he said he initially found Baltimore "too small-townish" for his liking and enrolled in night law school classes at the University of Baltimore.

But he soon became involved with the planning of the first City Fair, held in 1970 in downtown Baltimore. He left the paper to become executive director of the Citizens Planning and Housing Association, a post he held from 1970 to 1974.

Mr. Hartman, who lived on Maryland Avenue in Charles Village, tested the political waters in a 1974 Democratic race for the state Senate. He staged an unsuccessful primary challenge against incumbent Julian L. Lapides. He ran on a ticket with Macklyn McCarty Jr., Torrey C. Brown and Frank O. Heintz.

"He was bright, articulate and aggressive — and formidable," said Mr. Lapides. "He was a strong opponent, and he did a lot of good things for Baltimore."

Mr. Hartman's campaign literature said he was "Young, tough and nobody owns him."

After his defeat, he was tapped to lead a business group, the old Metropolitan Chamber of Commerce. A 1976 Sun profile called him a "surprise choice to head what was widely regarded as a moribund organization." The article continued, "Some say he is hot air. … He is a whirlwind in the normally sleepy role of executive vice president."

The Sun's account described Mr. Hartman: "His exterior is hard and he projects a slightly macho image: Long hours, a carton of cigarettes every two days, cigars, constant coffee. But he is gregarious in relaxation, as during a 5-hour celebration at Martick's recently to welcome the latest issue of the magazine," a reference to Baltimore Magazine, then owned and published by the chamber.

Mr. Hartman tapped J. Stanley Heuisler — and summoned him from a Tokyo hotel — to be the magazine's editor.

"He was clearly a key player, one of the disparate bunch of people who pulled off Baltimore's first big renaissance," Mr. Heuisler said. "I remember having dinner with him one night in London at Simpson's on the Strand. He looked like Winston Churchill. He was just always bigger than anyone and yet he was also a Damon Runyon kind of person. He could work both sides of the street. He understood the amalgam of the city. He could mix with Crown Central Petroleum's Henry Rosenberg or Locust Point's Shirley Doda."

In January 1979, he became Mr. Schaefer's press chief. When he left the post in 1982, the mayor said, "He's had a good working relationship with reporters and a very difficult person as his client."

A news article published at the time of his resignation called him "recognizable by his handlebar mustache and perpetually harried manner." It noted that he spent much of his time trying to keep both the Baltimore Colts and the Orioles in local ownership. He was president of the Designated Hitters, a group created to boost Orioles season ticket sales. He also tried to boost Colt ticket sales with a group called the Touchdowners.

"He was definitely a once-in-a-lifetime character," said David M. Gillece, a Cassidy Turley real estate manager. "He was the P.T. Barnum of Baltimore. He was a great fan of Irish songs. He had a voice, too, and would sing at the drop of a hat."

As part of his duties, Mr. Hartman mixed with out-of-town press when the Orioles lost to the Pittsburgh Pirates in the 1979 World Series. He also worked the media during a 1980 presidential debate at the Baltimore Convention Center.

"You can't buy an hour and a half on national TV," he told a Sun reporter in 1980. "We expect the debate will give the city a lot of exposure."

After leaving City Hall, he became a vice president and general manager of public relations at Richardson, Myers & Donofrio. Among his clients were Waterford Crystal, the old U.S. Fidelity and Guaranty insurance firm and the Maryland Million thoroughbred horse race. He remained active in political elections and organized fundraisers for Mr. Schaefer and other politicians.

Mr. Hartman was a board member of the Pride of Baltimore. He stood by Mr. Schaefer in 1986 after the first clipper replica sank returning from a visit to the Caribbean. A photo shows the mayor's downturned head shielded by his hand and an emotional Mr. Hartman standing above him.

Mr. Hartman went on to become secretary and a board member of the Baltimore Area Convention and Business Association.

His brother, Stephen Hartman of Perry Hall, said Mr. Hartman kept a poster of Mr. Schaefer attired in the bathing suit from the aquarium stunt in his apartment.

Funeral plans are incomplete.

In addition to his brother, survivors include his son, Russell Hartman of Austin, Texas; his father, Walter C. Hartman of Voorhees, N.J.; another brother, Jeffrey Hartman of Margate, N.J.; and three sisters, Jane Howard of Naples, Fla., Mariellen Etter of Delran, N.J., and Nancy Moeller of Voorhees. His marriages to Margaret Sweeney and Ann Stifler ended in divorce.